Clinical and biologic characteristics for recurring neuroblastoma at mass screening cases in Japan

BACKGROUND. It is said that most cases detected by neuroblastoma mass screening at 6 months of age tend to have a favorable clinical course after a surgical resection either with or without mild chemotherapy. However, a few cases have an unfavorable outcome. In the current study, the authors analyzed the clinical and biologic characteristics for recurring neuroblastoma in mass screening cases. METHODS. In 245 cases detected through mass screening in the Kyushu area in Japan, the clinical data and biologic features (N-myc status, DNA ploidy, Shimada histology, neuron-specific enolase (NSE), ferritin) were investigated, whereas, in particular, the data for recurring cases also were analyzed. RESULTS. Of 245 cases, 28 tumors had one or more biologically unfavorable prognostic factors, and 6 patients experienced recurrence. Three of the six patients with recurring disease underwent a complete resection of the primary tumor, whereas three cases had undergone an incomplete resection of the tumor. Regarding the initial chemotherapy, three cases received mild chemotherapy, two cases received no chemotherapy, and one case had high-dose multidrug chemotherapy. Regarding biologic prognostic factors, four of six cases with recurring disease had one or more unfavorable factors, whereas two cases had no unfavorable factors. Regarding the outcome after recurrence, four cases are CR, one case has a stable residual tumor, and one case died of disease with N-myc amplification. CONCLUSIONS. Most neuroblastomas detected by mass screening at 6 months of age have biologically favorable factors. However, approximately 10% of the cases had one or more unfavorable factors and thus might have a higher risk of recurrence than the patients with no unfavorable factors. Conversely, some cases with recurring disease had no unfavorable factors; however, the reason for this is still unclear. A long-term follow-up for mass screening cases is important, and it also might be necessary to research the established biologic factors and identify other new prognostic factors.